The trio were spotted on the roof of The Greetland Academy, on School Street in Greetland, earlier today.
They were overhead "discussing breaking something".
Principal Helen Crowther posted on the school's Facebook page: "I have been informed of three youths on our school roof at KS2 this afternoon.
Most Popular
-
1
School's out: 33 pictures of school leavers from Calderdale
-
2
Calderdale College launches partnership with Halifax youth organisation to improve access to life-changing opportunities
-
3
Sites are being explored for a new free school in south east Calderdale
-
4
Best and worst performing secondary schools in Calderdale for Attainment 8 according to latest league tables
-
5
Calderdale nursery shuts after 'Inadequate' Ofsted
"A member of the public took video footage and tried to challenge them. One of the three boys was dressed in a black puffer coat and had the word ICON across his front.
"When approached, he pulled a black bandana with a white pattern on over his face.
"Another had a back top and grey shorts with a bag across his front. The third had on grey joggers and a black top.
"I have passed this information on to the police. If anyone is able to identify them, please do let me know or contact the police.
"They were overheard discussing breaking something whilst on our roof.
"Many thanks to the member of the public who was trying to help our school.
"It is such a shame that these boys felt the need to endanger themselves and to break the law by trespassing."
Anyone with information about the incident can pass information to the police by calling 101 or using the live chat function on West Yorkshire Police's website.